Cero is a Barcelona based multidisciplinary design firm based with a focus on product design, engineering, graphic design, and programming. I recently discovered them by way of their Behance page, which features a few bike projects ranging from freeride and XC mountain bikes to an urban electric folding bike. On each of the Behance project pages, they provide a glimpse into the design process of the bikes with inspiration images, sketches, renderings, and prototype photos.